Re: DeLorean Transmission Gears

["Dave Swingle" <swingle@xxxx>]

I've done several of them. A basic "rebuild" consists of opening it 
up, cleaning, and replacing seals. You may also need to replace one 
of the rollpins that move the shft forks. 

You need the two paper gaskets, o-rings for the side flanges and the 
input shaft tube, the input shaft tube seal, and a tube of anerobic 
sealant. And a gallon of gear oil. All this adds up to under $100. 
I've pulled a trans, "rebuilt" and re-installed in a long day with 
some help. These things are actually very strong. The bearings seem 
to hold up very well. 

The manual is very accurate on the process with one or two 
exceptions, the main one being that the illustrations show the ring 
gear installed backwards (5 speeds in reverse, anyone?). Best to take 
pictures. 

The only special tool you need is a rig to hold the transmission 
still (i.e. not rolling across the floor) and a couple of rather 
large sockets to loosen and the re-torque the large mainshaft nuts. 
One is 32 MM, the other is slightly smaller (the size escapes me at 
the moment). Torque on these is 125 pounds, and the breakaway torque 
is a lot more. I use my door adjusting cheater bar to undo the shaft 
nuts. It's also good to buy replacment nuts, sometimes they break 
where they are staked over the end. 

Now for the complex part. 

Is the Lotus case different enough that you can't just swap in the 
whole thing? If you are only trying to swap in the ring and pinion, 
things get a lot more complicated. To get the ring gear off the 
carrier you have to remove one of the bearings (hydraulic press). To 
get the gears off the pinion shaft, there's a complex process 
involving heating up the parts and using a press. 

Stock DeLorean axle ratio is 3.44:1. A 3:8 or so gear in this car 
would make a huge difference. A 4:10 gear would really be a neck-
snapper but would limit your cruising ability - 5th gear would be 
about like your original 4th gear so the car would be pretty noisy 
and inefficient in highway driving. 

A couple of benchmarks - stock is 2800 RPM at 70 mph in 5th. 3.8 
would be 3120, 4:10 would be 3700. Ouch. 

Dave S



--- In dmcnews@xxxxxxxxxxxxxxx, MichaelRPack1@xxxx wrote:
> 
> What is necessary for a rebuild of the DeLorean 5-speed 
transmission? 
> 
> I was given a 1989 Lotus Esprit 5-speed transmission. I would like 
to switch the DMC (renault) gears for the Lotus (renault) gears. The 
transmissions are identical, and both 5-speeds are from Renault.
> 
> Any input from all of you would help. Any thoughts on what the 
different gear ratios would do to the PRV, especially the Houston PRV?
> 
> Sincerely,
> Michael Pack